twl6040 have two vibra output drivers.They can be operated with audio stream coming throughthe PDM interface (fifth channel).The vibra outputs can be controlled via the input/FFdriver as well.Selection between the two mode is implemented withinthe codec driver, the input/FF driver can only operate ifthe routing is set to "Input FF".Changing from "Input FF" to "Audio PDM" mode is protectedas well: The switchin can only be done, if there is norunning effect from the input/FF.